Several states have proposed anti-drone laws even as use of the unmanned aerial vehicles is increasing

Applications for domestic drone licenses are increasing steadily, even as privacy concerns related to the use of unmanned aerial vehicles (UAVs) over the U.S. continue to mount.

Government documents obtained by the Electronic Frontier Foundation (EFF) show that as of October 2012, 81 public entities had sought licenses from the Federal Aviation Administration (FAA) to operate drones. In fact between August and October, the FAA's drone authorization list grew more than 33%, from 60 applicants to 81 applicants.

Those who have applied for authorization include local police departments, the U.S. State Department, the National Institute of Standards and Technology, several universities and an Indian tribal agency.

The growing number of drone license applications comes amid mounting privacy and security concerns over their use. Earlier this week, Charlottesville, Va. became the first city in the U.S. to pass a resolution banning drones from its airspace "to the extent compatible with federal law."

The resolution prohibits city agencies from buying, leasing, borrowing or testing drones and provides a maximum penalty of up to one year in jail and a fine for up to $10,000 for violators. Charlottesville's anti-drone resolution cites several security and privacy issues as reasons for the ban.

On Wednesday, an anti-drone bill in Florida advanced when the Senate Committee on Community Affairs unanimously approved the measure 9-0. The bill prohibits state law enforcement agencies from using drones to gather evidence or information during investigations. It also prohibits the use of evidence gathered by drones in any criminal prosecution in any court in the state.

The bill does provide an exception to counter terrorist attacks and other high-risk security situations as determined by the U.S. Department of Homeland Security. If approved, Florida's anti-drone bill would go into effect on July 1.

A similar bill introduced in the Texas legislature on Feb 1 seeks to restrict the use of images captured by drones flying over public and private property in the state. The Texas Privacy Act (H.B. 912) would make it an offense for any drone operator in the state to capture images of people on private property without the explicit permission of the person, unless the image was obtained using a valid search warrant.

Police in immediate pursuit of criminal suspects would be exempt from the prohibition, as would first responders in emergency situations.

Earlier this week, the Montana Senate approved by a wide margin a bill that prohibits state government agencies from using or owning unmanned aerial vehicles in Montana. Several other states, including Missouri, Virginia, Nebraska and Oregon are also considering legislation to curb drone use.

It remains unclear how effective or meaningful such measures will be, given that the FAA has the final say over U.S. airspace. Even so, the bills highlight the high level of concern that has been stoked by the passage of the Federal Aviation Administration Modernization and Reform Act of 2012.

That measure was signed into law by President Barack Obama last February and permits commercial UAVs to operate over U.S. airspace. The bill has put the FAA in charge of issuing licenses to drone operators and ensuring that they are operated safely.

The statute will initially let law enforcement authorities and emergency services use drones that weigh less than five pounds and fly at an altitude of less than 400 feet. But it requires that the FAA have rules in place permitting the use of all varieties of drones by law enforcement and private entities by the end of 2015. By some estimates, there could be as many as 30,000 drones operating over U.S. skies in the next few years.

Proponents of drone use, including the influential Association for Unmanned Vehicle Systems International (AUVSI) argue that drones can be extremely useful in a wide range of areas, including law enforcement, traffic management, crop monitoring, land management, news reporting, real estate sales and filmmaking. They have consistently downplayed concerns related to domestic use and have said that the benefits far outweigh any concerns.

"Unmanned aircraft have the potential to help law enforcement agencies with missions such as search and rescue or crime scene photography, often at a lower cost than manned aircraft," a spokeswoman from UAVSI said. "While there certainly should be a reasonable conversation about the application any new technology, we are concerned by any proposed legislation that might unnecessarily limit law enforcement agencies' ability to use unmanned aircraft to keep communities safe."

Critics, including numerous federal and state lawmakers, rights groups, privacy advocates and academicians maintain that drone use without meaningful new privacy safeguards is extremely dangerous.

They have noted that drones with facial recognition cameras, license plate scanners, thermal imaging cameras, open Wi-Fi sniffers and other sensors could be easily used for general public safety surveillance in violation of privacy laws and constitutiona rights.

In a report released Jan. 30, the Congressional Research Service noted that the integration of drones into domestic airspace raises myriad new privacy and legal issues. Among the issues highlighted in the report are concerns about the right to protect private property against trespassing drones.

"There are a host of related legal issues that may arise with this introduction of drones in U.S. skies," the report said. "These include whether a property owner may protect his property from a trespassing drone; how stalking, harassment, and other criminal laws should be applied to acts committed with the use of drones; and to what extent federal aviation law could preempt future state law."